Vrana Andrea, Meier Michael L, Hotz-Boendermaker Sabina, Humphreys Barry K, Scholkmann Felix
Interdisciplinary Spinal Research, Department of Chiropractic Medicine, University Hospital BalgristZürich, Switzerland; Department of Health Sciences and Technology, Human Movement Sciences and Sport, ETH ZürichZürich, Switzerland.
Interdisciplinary Spinal Research, Department of Chiropractic Medicine, University Hospital Balgrist Zürich, Switzerland.
Front Hum Neurosci. 2016 Nov 17;10:578. doi: 10.3389/fnhum.2016.00578. eCollection 2016.
In this study we investigated sensorimotor processing of painful pressure stimulation on the lower back of patients with chronic lower back pain (CLBP) by using functional near-infrared spectroscopy (fNIRS) to measure changes in cerebral hemodynamics and oxygenation. The main objectives were whether patients with CLBP show different relative changes in oxy- and deoxyhemoglobin ([OHb] and [HHb]) in the supplementary motor area (SMA) and primary somatosensory cortex (S1) compared to healthy controls (HC). Twelve patients with CLBP (32 ± 6.1 years; range: 24-44 years; nine women) and 20 HCs (33.5 ± 10.7 years; range 22-61 years; eight women) participated in the study. Painful and non-painful pressure stimulation was exerted with a thumb grip perpendicularly to the spinous process of the lumbar spine. A force sensor was attached at the spinous process in order to control pressure forces. Tactile stimulation was realized by a one-finger brushing. Hemodynamic changes in the SMA and S1 were measured bilaterally using a multi-channel continuous wave fNIRS imaging system and a multi-distant probe array. Patients with CLBP showed significant stimulus-evoked hemodynamic responses in [OHb] only in the right S1, while the HC exhibited significant [OHb] changes bilaterally in both, SMA and S1. However, the group comparisons revealed no significant different hemodynamic responses in [OHb] and [HHb] in the SMA and S1 after both pressure stimulations. This non-significant result might be driven by the high inter-subject variability of hemodynamic responses that has been observed within the patients group. In conclusion, we could not find different stimulus-evoked hemodynamic responses in patients with CLBP compared to HCs. This indicates that neither S1 nor the SMA show a specificity for CLBP during pressure stimulation on the lower back. However, the results point to a potential subgrouping regarding task-related cortical activity within the CLBP group; a finding worth further research.
在本研究中，我们通过使用功能近红外光谱（fNIRS）测量脑血流动力学和氧合变化，来研究慢性下腰痛（CLBP）患者下背部疼痛性压力刺激的感觉运动处理。主要目的是与健康对照（HC）相比，CLBP患者在辅助运动区（SMA）和初级体感皮层（S1）中氧合血红蛋白和脱氧血红蛋白（[OHb]和[HHb]）的相对变化是否不同。12名CLBP患者（32±6.1岁；范围：24 - 44岁；9名女性）和20名HC（33.5±10.7岁；范围22 - 61岁；8名女性）参与了该研究。使用拇指握力垂直于腰椎棘突施加疼痛性和非疼痛性压力刺激。在棘突处连接一个力传感器以控制压力。通过单指轻刷实现触觉刺激。使用多通道连续波fNIRS成像系统和多距离探头阵列双侧测量SMA和S1中的血流动力学变化。CLBP患者仅在右侧S1中显示出[OHb]的显著刺激诱发血流动力学反应，而HC在SMA和S1双侧均表现出显著的[OHb]变化。然而，组间比较显示，两种压力刺激后，SMA和S1中[OHb]和[HHb]的血流动力学反应无显著差异。这一不显著的结果可能是由患者组内观察到的血流动力学反应的高个体间变异性所驱动。总之，与HC相比，我们在CLBP患者中未发现不同的刺激诱发血流动力学反应。这表明在对下背部进行压力刺激期间，S1和SMA对CLBP均无特异性。然而，结果指出了CLBP组内与任务相关的皮层活动可能存在亚组划分；这一发现值得进一步研究。
